输出纹波最小化有源箝位正激磁集成变换器

传统有源箝位变换器存在输出电流脉动较大的缺点。利用磁集成技术将电感和变压器的交变磁通正向耦合，以减小有源箝位变换器的输出电流脉动。该文提出磁集成有源箝位正激变换器，并对其工作原理进行分析。通过将零纹波点设定在0.5占空比处，使变换器同时得到最小输出电流纹波和最低原边开关管的电压应力。给出集成磁件的设计公式以及原边电流脉动和输出电流脉动的表达式。通过2台100 W磁集成和传统式的有源箝位正激变换器的实验对比，验证了理论分析的正确性。实验表明，与传统变换器相比，磁集成有源箝位变换器具有更高的变换效率和更小的输出纹波。

Active Forward Converter with Integrated-magnetics and the Minimum Output Ripple Current

The large output ripple current impaired the performance of active clamp forward (ACF) converter. By the AC flux positive coupling of the inductor and transformer, the output ripple current can be reduced. The improved ACF converter with integrated magnetics was proposed in this paper. The operation principle of the proposed converter was analyzed in detail. By setting D = 0.5 as the zero ripple current point, the minimized output ripple current and minimized voltage stress of primary switches were achieved simultaneously. The design consideration for the integrated magnetics was discussed along with the effect on the ripple currents. Two 100 W ACF prototype converters, with integrated magnetics and without, were built to verify the operation principle. Experimental results also proved that the proposed ACF converter has higher efficiency and lower output ripple current compared with conventional one.